Chick is not absorbing the yolk

I need help plz, most of my chicks are hatching very weak and the yolk is not absorbed fully. What do u think may be the problem? Half of them are not even hatching , they are dying in the shell With alot of egg yolk hanging out the chick.

The chicks are hatching on time. Temperature is steady at 37.5 an humidity at 50%.I've got the eggs stored in a chiller before incubation, I was also still having this problem before storing in the chiller.